Don't guess basedir in mysql_config; we place it under _libdir because
of multilib conflicts, so use rather configured @prefix@ path directly.

diff -up mariadb-5.5.40/scripts/mysql_config.sh.p14 mariadb-5.5.40/scripts/mysql_config.sh
--- mariadb-5.5.40/scripts/mysql_config.sh.p14	2014-09-04 07:54:41.378332895 +0200
+++ mariadb-5.5.40/scripts/mysql_config.sh	2014-09-04 07:55:24.633788157 +0200
@@ -77,7 +77,7 @@ get_full_path ()
 me=`get_full_path $0`
 
 # Script might have been renamed but assume mysql_<something>config<something>
-basedir=`echo $me | sed -e 's;/bin/mysql_.*config.*;;'`
+basedir='@prefix@'
 
 ldata='@localstatedir@'
 execdir='@libexecdir@'